Setting permissions using symbolic notation has some advantages over numeric including the ability to add or subtract permissions. Another advantage may be that there's no math involved in setting permissions, a user would choose which flags to set r for read, w for write and x for execute and then assign them to the file using chmod. Symbolic mode however requires more typing on the commandline.
- [Instructor] There are two different methods…of setting permissions in Linux, Numeric, and Symbolic mode.…Let's talk about Symbolic mode.…We have three positions in Linux permissions,…User Owner, Group Owner, and Other.…We can set read, write, and execute permissions…on files and directories.…In Symbolic mode, we assign a value to each position,…using symbolic representation of the desired permissions.…To set read, write, and execute for the User Owner,…we just specify u equals rwx.…
To set read and execute for the Group Owner,…we'd use g equals rx.…To set permissions to nothing for Other,…just do o equals, with nothing after it.…To set permissions for multiple positions at one time,…just separate them with a comma.…For instance, u equals rwx comma g equals rx comma…o equals.…With Symbolic method, we can also add permissions…by changing the equals sign to a plus.…
To add rwx for the user, we would use, u plus rwx.…To subtract permissions, replace the equals sign…with a hyphen.…To take execute permissions away from Other,…
- Define file Access Control Lists.
- Describe what extended globs add to Linux pattern matching.
- State why file system recovery tools are so important for Linux users.
- Recall what execute permissions on a directory allows.
- Cite the maximum allowed default permissions on a file in Linux.
- List some of the advantages of ACLs over standard Unix permissions.